Question

question 5
which of the following is not a piece of equipment used in the sodium bicarbonate experiment?

• an acid - base indicator
• a source of heat (either flame or hot plate)
• a spectrophotometer
• a balance or scale

question 6
which of the following is not a step used in the sodium bicarbonate experiment?

• the contents of the test tube is weighed both before and after heating.
• an acid - base indicator is used to find the ph of the white powder.
• an empty test tube is weighed at the beginning of the lab.
• the heated baking soda test tube is cooled to room temperature before weighing.

question 7
what test would be used to check that the gas released in a chemical reaction w carbon dioxide?

• gas extinguishes a glowing wood splint
• gas gives a \pop\ sound when tested with glowing wood splint.
• gas reignites the smoldering wood splint.

Explanation:

Question 5

In a sodium bicarbonate experiment (usually involving decomposition, pH testing, or mass change), an acid - base indicator is used to test pH, a heat source is used for heating, and a balance is used to measure mass. A spectrophotometer is used for measuring light absorption (e.g., in spectroscopy - based experiments, like analyzing colored solutions or compounds), which is not part of a typical sodium bicarbonate experiment.

In a sodium bicarbonate experiment (e.g., decomposition to study mass change), we weigh the empty test tube, weigh the test tube with contents before and after heating, and cool the heated test tube before weighing (to ensure accurate mass measurement). Using an acid - base indicator to find the pH of the white powder is not a typical step in a sodium bicarbonate decomposition or mass - related experiment (the focus is usually on mass change or gas production, not pH of the powder in this context).

Carbon dioxide ($\ce{CO_2}$) is non - flammable and does not support combustion. So it extinguishes a glowing wood splint. A "pop" sound is for hydrogen gas (when tested with a burning splint), and reigniting a smoldering splint is for oxygen.

Answer:

C. a spectrophotometer

Question 6